2157664 has 12 divisors (see below), whose sum is σ = 4247964. Its totient is φ = 1078816.

The previous prime is 2157641. The next prime is 2157667. The reversal of 2157664 is 4667512.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2157667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33682 + ... + 33745.

It is an arithmetic number, because the mean of its divisors is an integer number (353997).

2^2157664 is an apocalyptic number.

It is an amenable number.

2157664 is a deficient number, since it is larger than the sum of its proper divisors (2090300).

2157664 is an equidigital number, since it uses as much as digits as its factorization.

2157664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67437 (or 67429 counting only the distinct ones).

The product of its digits is 10080, while the sum is 31.

The square root of 2157664 is about 1468.8989073452. The cubic root of 2157664 is about 129.2194649685.

The spelling of 2157664 in words is "two million, one hundred fifty-seven thousand, six hundred sixty-four".